Panel adhesive

[Alaska Mike]

OK, I'm going to plead complete ignorance here, and I know there are some people that work in the auto body industry here. If this is a dangerous option, please let me know.

Here's my situation:
The footwells of my Series III bulkhead are shot, and I've removed the passenger side completely and have finished the prep work in order to install the new footwell.

Here's a suggestion I got:
Instead of welding, use panel adhesive to bond the footwells to the bulkhead. I have to admit, this is tempting given my crappy 110V flux core welder and my less-than-stellar welding skills. However, I've never used them and my quick internet research has left me more than a little confused.

My question:
Would an automotive panel adhesive be appropriate in the situation? Most of the places where the footwell meets the bulkhead have a 1" or better overlap, providing what I think is ample surface area for an adhesive. While I know I can get sufficient bonding with the 110V wire feed, would the more compete bonding of the adhesive be stronger? Would a combination of the two be feasible? Rivets?

Thanks for any advice here. "Correct" doesn't even come into the picture here. Structurally sound does.

 

[stevenmd]

It seems like a combination of the two would be best - structurally sound and waterproof.:snorkel: Just make sure the adhesive isn't flammable when you go to weld... :chef:

 

[I Leak Oil]

As long as the new parts are tied into the rest of the bulkhead in all the right places you'll be fine with the panel adhesive. The modern adhesives are plenty strong and maybe even stronger than a welded assembly. When you make your lap joint just make sure they're like a roof shingle where the high side overlaps the low side on the exterior.

 

[R_Lefebvre]

I don't really like the idea frankly, I just think welding it in would be better in the long run. That being said, some of the best cars in the world are bonded together (Lotus, for example).

I don't think you could combine them. The weld heat would surely destroy the adhesive.

 

[Alaska Mike]

I don't really like the idea frankly, I just think welding it in would be better in the long run. That being said, some of the best cars in the world are bonded together (Lotus, for example).

I don't think you could combine them. The weld heat would surely destroy the adhesive.

Yeah, I was wondering about that. I was considering mixing riveting and panel adhesive as well, which eliminates the heat.

Here's a link that seriously got me thinking:
http://www.autobodypro.com/tektips/articles/panel.htm

 

[ntsqd]

Yeah, I was wondering about that. I was considering mixing riveting and panel adhesive as well, which eliminates the heat.

Here's a link that seriously got me thinking:
http://www.autobodypro.com/tektips/articles/panel.htm

The Lola T8990 that I worked on back in '89 had a riveted & bonded monocoque. That tub was very stiff. Done well I would have no issue with this method at all, though knowing what, if any, agents act as a solvent on the adhesive would be prudent.

Interesting article, thanks for the link!

 

[Alaska Mike]

Again, I'm not advocating it- I'm looking for opinions on if it would be suitable in that application. It was suggested as an option, and now all I'm doing is exploring it. Might happen, might not.

The solvent and UV resistance is a concern for me, although in that location it's not going to see much daylight. The protection from corrosion is an interesting side effect, although my goal is still to have a solid structure. That BMW uses it to bond frames (although likely in a different formulation) is an interesting look at how far the technology has come.

 

[Mercedesrover]

Mike - Just in from a 700-mile road trip back from northern Ontario and I'm beat. I'll write more in the morning, but yes, panel bonding adhesive would be fine here.

 

[revor]

From the xpurt!:sombrero:

How was the weather?:elkgrin:

Mike - Just in from a 700-mile road trip back from northern Ontario and I'm beat. I'll write more in the morning, but yes, panel bonding adhesive would be fine here.

 

[Alaska Mike]

Mike - Just in from a 700-mile road trip back from northern Ontario and I'm beat. I'll write more in the morning, but yes, panel bonding adhesive would be fine here.

Any advice , suggestions, or whatever would be appreciated. What brand would you suggest? I'm all ears, and I'm seriously considering this option.

 

[Mercedesrover]

From the xpurt!:sombrero:

How was the weather?:elkgrin:

Expert? Hardly!

Cold up thar!! Wendy's folks are 3 hours north of Toronto. Nice country. They leave 8 feet of all the roadsides un-plowed for the snowmobiles. Very cool.

 

[Mercedesrover]

Any advice , suggestions, or whatever would be appreciated. What brand would you suggest? I'm all ears, and I'm seriously considering this option.

We use 3M brand #8115. Good strong stuff and easy to work with. You'll need the applicator gun to apply it but I bet if you go into a bodyshop and ask them to borrow it for an evening, they'd probably let you.

It's not hard to work with but you need to make sure you have clean, dry surfaces that fit tightly together. Here's the 3M wall chart on how to work with this stuff. Make sure you grind/wire brush/sand the two surfaces that you're mating. You'll need lots of test-fitting to get it right. You'll also want to borrow a bunch of large C-clamp Vise Grips to hold everything together. An alternative is to drill holes and use a series of screws to hold the two panels together. It cures in 12-24 hours and is very strong when it does. While it is still liquid you can brush it around and use it as a seam-sealer.

 

[jopadorr]

Bonding footwells

I am not a welder and can only make ugly pathetic attempts at welded repairs. I was in a similar position and chose to use a small steel closed end pop rivet to hold the footwells in place. I then used a 110V flux core wire welder to make several very small spot welds- I mean small- just enough to make a small puddle- the machine was set on its lowest setting and slowest feed. All the spots were placed where they would not be seen once the truck is assembled. My plans are to galvanize the bulkhead once I have finished all the repairs. The steel closed end rivets will end up being small globs of galvanizing.
I think for a bulkhead not being galvanized the panel adhesive method would be fine...also dont be afraid to make some small spot like rosette welds- it takes no technique...-John